It seems to me that the greatest offensive boxer in the history of modern boxing was Harry Greb. Consider the following:

1. He's the first man to hand defeats to Tunney (and the only) and Tommy Gibbons, both of whom are among the greatest LHWs ever. Greb was totally outgunned and outsized.

2. By all accounts, the man's punch stats would be off the charts.

3. This was the era of 5 ounce gloves. Greb was taking shots from guys far bigger than him as a matter of course. He didn't care about size, power, color --nothing.

4. Most of his greatest victories occured when he was blind or practically blind in one eye.

5. You don't beat Mickey Walker unless you are a serious offensive machine.

6. This year marks an anniversary. Greb had 45 fights in 1919. That's an average of a fight every 8 days. You name the style, he faced it that year. Middleweights, light heavyweights, and heavyweights. And guess what... no one beat him. 45-0 that year. Floyd, Ray Leonard had less fights in their totalcareer than Greb had in one year. Greb had 300 fights when he was done -67 practically blind. And he kicked the **** out of a prime Dempsey -who others have mentioned out here as a top offensive fighter.

....
Armstrong? Greb was his daddy. Robinson? compared to Greb, he's conquests were limited... Ray was Carthage to Greb's Rome.

No one else that I can think of is even close. And that's not all, Greb was defensively surreal -but that's another thread.